Chapter 32. Configuring ethtool coalesce settings

Using interrupt coalescing, the system collects network packets and generates a single interrupt for multiple packets. This increases the amount of data sent to the kernel with one hardware interrupt, which reduces the interrupt load, and maximizes the throughput.

This section provides different options to set the ethtool coalesce settings.

32.1. Coalesce settings supported by NetworkManager

You can set the following ethtool coalesce settings using NetworkManager:

  • coalesce-adaptive-rx
  • coalesce-adaptive-tx
  • coalesce-pkt-rate-high
  • coalesce-pkt-rate-low
  • coalesce-rx-frames
  • coalesce-rx-frames-high
  • coalesce-rx-frames-irq
  • coalesce-rx-frames-low
  • coalesce-rx-usecs
  • coalesce-rx-usecs-high
  • coalesce-rx-usecs-irq
  • coalesce-rx-usecs-low
  • coalesce-sample-interval
  • coalesce-stats-block-usecs
  • coalesce-tx-frames
  • coalesce-tx-frames-high
  • coalesce-tx-frames-irq
  • coalesce-tx-frames-low
  • coalesce-tx-usecs
  • coalesce-tx-usecs-high
  • coalesce-tx-usecs-irq
  • coalesce-tx-usecs-low

32.2. Configuring ethtool coalesce settings using NetworkManager

This section describes how to set ethtool coalesce settings using NetworkManager, as well as how you remove the setting from a NetworkManager connection profile.


  1. For example, to set the maximum number of received packets to delay to 128 in the enp1s0 connection profile, enter:

    # nmcli connection modify enp1s0 ethtool.coalesce-rx-frames 128
  2. To remove a coalesce setting, set the setting to ignore. For example, to remove the ethtool.coalesce-rx-frames setting, enter:

    # nmcli connection modify enp1s0 ethtool.coalesce-rx-frames ignore
  3. To reactivate the network profile:

    # nmcli connection up enp1s0

Verification steps

  1. Use the ethtool -c command to display the current offload features of a network device:

    # ethtool -c network_device

Additional resources